The "New York Times" bestselling series. As the race to find the 39 Clues builds to its explosive finish, Amy and Dan must steal a Clue guarded by thousands of the world's best soldiers. With their enemies closing in, the siblings are separated. Together, they almost have a chance, but alone ... Could the search for this Clue spell the end of Amy and Dan?

Rick Riordan is the author of the New York Times #1 best-selling The Lost Hero, the first book in the Heroes of Olympus series. Kids across the country voted him Author of the Year for that book through the Children's Book Council in association with Every Child a Reader. Rick also penned the New York Times #1 best-selling Percy Jackson and the Olympians series: Book One: The Lightning Thief, Book Two: The Sea of Monsters, Book Three: The Titan's Curse, Book Four: The Battle of the Labyrinth and Book Five: The Last Olympian. The first two books in his Kane Chronicles, based on Egyptian mythology, The Red Pyramid and The Throne of Fire, were New York Times #1 best sellers as well. Rick lives in San Antonio, Texas, with his wife and two sons.